[go: up one dir, main page]

US3061757A - Circuit arrangement to produce a sawtooth current in a coil and a direct voltage - Google Patents

Circuit arrangement to produce a sawtooth current in a coil and a direct voltage Download PDF

Info

Publication number
US3061757A
US3061757A US793483A US79348359A US3061757A US 3061757 A US3061757 A US 3061757A US 793483 A US793483 A US 793483A US 79348359 A US79348359 A US 79348359A US 3061757 A US3061757 A US 3061757A
Authority
US
United States
Prior art keywords
voltage
circuit
current
transformer
variation
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US793483A
Other languages
English (en)
Inventor
Janssen Peter Johanne Hubertus
Smeulers Wouter
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
US Philips Corp
North American Philips Co Inc
Original Assignee
US Philips Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by US Philips Corp filed Critical US Philips Corp
Application granted granted Critical
Publication of US3061757A publication Critical patent/US3061757A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N3/00—Scanning details of television systems; Combination thereof with generation of supply voltages
    • H04N3/10—Scanning details of television systems; Combination thereof with generation of supply voltages by means not exclusively optical-mechanical
    • H04N3/16—Scanning details of television systems; Combination thereof with generation of supply voltages by means not exclusively optical-mechanical by deflecting electron beam in cathode-ray tube, e.g. scanning corrections
    • H04N3/18—Generation of supply voltages, in combination with electron beam deflecting
    • H04N3/185—Maintaining DC voltage constant
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N3/00—Scanning details of television systems; Combination thereof with generation of supply voltages
    • H04N3/10—Scanning details of television systems; Combination thereof with generation of supply voltages by means not exclusively optical-mechanical
    • H04N3/16—Scanning details of television systems; Combination thereof with generation of supply voltages by means not exclusively optical-mechanical by deflecting electron beam in cathode-ray tube, e.g. scanning corrections
    • H04N3/18—Generation of supply voltages, in combination with electron beam deflecting

Definitions

  • the invention relates to a circuit arrangement for producing a sawtooth current in a coil and a direct voltage with the aid of an amplifiying element, to which a signal is fed, which releases periodically the said element, the output circuit of the arrangement including a transformer, of which the primary winding, with which the coil is coupled, is connected at one end, if desired via a capacitor, to one terminal of a voltage source, the other terminal of which is connected to the amplifying element, whilst the other terminal of the primary winding is connected to the output terminal of the amplifying element and the pulses produced across this primary winding during the fly-back of the sawtooth current are rectified subsequent to a step-up by a secondary winding on the transformer.
  • the circuit arrangement according to the invention is based on the recognition of the fact that, since it is impossible to keep constant both the deflection current and the voltage for feeding the final anode of the picture tube it is desirable to vary the two factors so that in spite of variations of the two magnitudes, prior to and after the variation, an unambiguous relationship is maintained between them.
  • the circuit arrangement according to the invention is therefore characterized in that provision is made of means which, in the event of variations, particularly of variations in the load of the direct voltage produced, cause the amplitude of the sawtooth current and the direct voltage produced to vary accordingly in a manner such that, within the range of operation, the relative variation in the said amplitude is about half the relative variation of the said direct voltage.
  • FIG. 1 shows a first embodiment of the arrangement according to the invention, in which the negative feedback circuit employed compensates only partly the potential variations in the deflection current.
  • FIGS. 2 and 3 serve for further explanation and FIGS. 4 and 5 show further embodiments of the arrangement according to the invention.
  • a control-voltage 2 is fed via a capacitor 3 and a leakage resistor 4 to the control-grid 5 of a tube 1, which is periodically released by this control-voltage.
  • the mbe 1 is the output tube of the horizontal-deflection circuit and the anode current produced by tube 1 passes through the primary winding of the transformer Sand, with the aid of the booster diode 6, it produces through the coil 10, a sawtooth current with an amplitude I
  • the lower end of the primary winding is connected, via the capacitor 7, associated with the booster diode circuit, to the positive terminal of a voltage source (not shown), of which the negative terminal is connected to earth and which provides a voltage V,,.
  • the anode of the diode 6 is also connected to the positive terminal of this voltage source.
  • the pulses produced across the primary winding of the transformer 8 during the fly-back of the sawtooth current are stepped up via the secondary winding and rectified by the rectifier 9, so that, subsequent to smoothing, a direct voltage V is obtained, which is used to feed the final anode of the picture tube.
  • the coil 10 surrounds the neck of the picture tube (not shown) and the current passing through the coil 10 produces a magnetic field, which deflects the electron beam in the horizontal direction.
  • the deflection current For a given extent of deflection d of the electron beam on the screen of the picture tube and With a voltage V the deflection current must, in general, fulfil the condition.
  • i K /V wherein i is the instaneous value of the sawtooth current, V the acceleration voltage of the electrons and K a proportionality constant, which varies with the extent of deflection d and the tube constants.
  • a control circuit 13 consisting of a capacitor 12, which supplies the alternating voltage from a tapping of the primary winding of the transformer to the element 14, which has a non-linear current-voltage characteristic curve, and of a resistance element 11, which provides the direct-current connection between the said tapping and the element 14.
  • the element 11 furnishes, so to say, a positive bias votlage for the element 14, across which a negative voltage is produced, in the case of an adequate amplitude of the pulses produced across the primary winding of the transformerr8.
  • This voltage being stored by the capacitor 12 for that part of the period for which the pulses are not operative.
  • the nega- 3. tive voltage thus obtained is supplied via the leakage resistor 4 to the control-grid 5.
  • the element 14 may be constituted by a voltagedependent resistor (VDR-resistor); in this embodiment the tapping to which the elements 11 and 12 are connected is the same as that to which one end of the coil 10 is connected, but this is not at all required in all cases.
  • the tapping may comprise a greater or smaller number of turns of the primary winding of the transformer 8 in accordance with the amplitude of the pulses to be fed to the element 14.
  • tapping may also be provided on the secondary winding of the transformer 8.
  • V the extent of deflection D in the horizontal direction on the screen would vary, since the conditions of (l) are no longer fulfilled owing to the residual variation of one of the two magnitudes.
  • FIG. 2 shows an equivalent diagram of the arrangement shown in FIG. 1.
  • Z /n 2 /11 and I .n designate the high-voltage load transferred to the primary of the transformer 8 (picture tube plus circuit elements), the impedance between primary and secondary (mainly the stray inductance of the transformer 8) and the current passing through the picture tube respectively.
  • Z is the total impedance constituted by the deflection circuit and l is the amplitude of the said deflection current, whilst R is the primary internal resistance constituted by the tube 1, the diode 6 and the primary winding of the transformer 8.
  • V' varies, since Z and Z are constant and it follows therefrom that (1) is not fulfilled.
  • FIG. 3a The first case is illustrated in FIG. 3a, in which the deflection current I and the high voltage V are indicated as a function of the load B (variation in the current through the picture tube). If B designates the minimum load and if, at this load, the equation (1) is fulfilled, it will be evident that this does not apply to any other load.
  • the desired result is obtained by causing the two magnitudes to vary simultaneously, as is illustrated in FIG. 3b.
  • K is a proportionality constant
  • a separate rectification of the pulses obtained from the transformer may provide a direct voltage, which, upon a variation in l will vary in the manner indicated by the Equation 10. By using this voltage in the same manner as the voltage V the condition (6a) can again be fulfilled.
  • FIG. 4 A further method of obtaining the said purpose is illustrated in FIG. 4.
  • the elements 16 and 15 are provided between the primary and the secondary winding of the transformer 8. The windings remain in magnetic contact with each other via the core of the transformer.
  • the resistor 15 constitutes the direct-current path and is traversed by the load current.
  • the capacitor 16 provides the alternating-current coupling and constitutes an easy path for the fly back pulses.
  • the resistor 11, which provides the direct-current adjustment of the element 14, is connected to the junction of the resistor 15 and one end of the secondary winding of the transformer 8.
  • the arrangement shown in FIG. operates on the same principle as the arrangement shown in FIG. 4.
  • Only the control-circuit 13 is modified and consists of an amplifying tube 18, to which the pulses of the tapping of the transformer 8 are fed via the capacitors 19 and 20.
  • the bias voltage for this tube is obtained with the aid of an element 17, which as the element 14, has a nonlinear current voltage characteristic curve and which is connected at one end to earth and at the other to the resistor 11. Also in this case the bias voltage is varied in accordance with the load current, so that the negative voltage produced by the amplifying tube 18 decreases,
  • the information regarding the variations in V owing to load variations may also be obtained directly from the high-voltage circuit by connecting the cathode of the rectifier 9 via a suitable potentiometer to the element 14 of FIG. 4 or to the cathode of the tube 18 of FIG, 5.
  • the transformer need not be proportioned in accordance with Formula 9, but it will be obvious that by a correct proportioning of the total control-circuit the apparent primary internal impedance R and the apparent secondary impedance Z /n are readjusted so that again Formula 9 is fulfilled. Since the two lastmentioned arrangements are pure control-circuits, a correct proportioning in capable of ensuring that, if Z remains constant, the variations due to a variation in the supply voltage or to ageing of the elements 1 and 6 are readjusted as far as possible. This may be obtained by keeping I substantially constant with the aid of the information obtained from the primary winding of the transformer. Since the Z value has remained constant, V will not vary, neither the deflection of the electron beam. Since neither V nor Z vary, the voltage supplied to the control-circuit via the resistor 11 will remain constant, so that in this case no additional variations will occur in the control-circuit.
  • discharge tube 1 may be replaced by a power transistor.
  • the diodes 6 and 9 may be constituted by any suitable unilaterally conductive element.
  • a circuit for producing a direct voltage and a current with a sawtooth wave form in a coil comprising an amplifying element having an input and output circuit, means applying a signal to said input circuit for periodically rendering said amplifying device conductive, said output circuit comprising a transformer having a primary and secondary winding, means connecting said coil to an end of said primary winding, means connecting one end of said primary winding to a source of voltage and the other end of said primary winding to an output electrode of said amplifying device, rectifier means connected to one end of said secondary winding for producing a direct voltage, and means for eflecting variation of the amplitude of said sawtooth current with variation of said direct voltage such that the relative variation of said amplitude is approximately half of the relative variation of said direct voltage, the internal resistance R of said amplifying element, the impedance Z; of said coil transferred to said other end of said primary winding, and the internal impedance 2 /11 of the secondary side of said transformer transferred to the primary side, being related as follows where n is the transformation ratio of
  • a circuit for producing a direct voltage and a current with a sawtooth wave form in a coil comprising an amplifying element having an input and output circuit, means applying a signal to said input circuit for periodically rendering said amplifying device conductive, said output circuit comprising a transformer having a primary and secondary winding, means connecting said coil to an end of said primary winding, means connecting one end of said primary winding to a source of voltage and the other end of said primary winding to an output electrode of 7 said amplifying device, rectifier means connected to one end of said secondary Winding for producing a direct voltage, and means for effecting variation of the amplitude of said sawtooth current with variation of said direct voltage such that the relative variation of said amplitude is approximately half of the relative variation of said direct voltage, a control circuit having a first input terminal coupled to said primary winding, a second input terminal, and an output circuit connected to the input circuit of said amplifying element, and means connected to said secondary winding applying a voltage to said second input terminal that varies with the load on the produced direct
  • said amplifying element comprises a discharge tube, comprising means applying said signal to the control grid of said tube, and means connecting said one end of said primary winding to the positive terminal of said voltage source by way of a capacitor, said output electrode comprising the anode of said tube.
  • control circuit comprises a second biased discharge tube
  • said first input terminal comprising, means connecting the control grid and anode of said second tube by way of separate capacitor means to a tap on said transformer, an impedance element connected between the anode of said second tube and the control grid of said first tube, and said second input terminal being connected to the cathode of said second tube to provide a bias for said second tube that varies with the load on said produced direct voltage.
  • control circuit comprises a device having a non-linear voltage current characteristic curve, means connecting one end of said element to the negative terminal of said voltage source, means connecting the other end of said device to said grid of said tube, a network connected between the other end of said secondary winding and said other end of said primary winding, said second input terminal comprising re sistance means connecting said other end of said secondary winding to said other end of said device, and said first input terminal comprising capacitor means connected between said other end of said device and a tap on said primary winding.
  • a circuit for producing a direct voltage and a current with a sawtooth wave form in a coil comprising an amplifying element having an input and an output circuit, means applying a signal to said input circuit for periodically rendering said amplifying device conductive, said output circuit comprising a transformer having a primary and a secondary winding, means connecting said coil to an end of said primary winding, means connecting one end of said primary winding to a source of voltage and the other end of said primary winding to an output electrode of said amplifying device, rectifier means connected to one end of said secondary winding for producing a direct voltage, means for effecting variation of the amplitude of said sawtooth current with variation of said direct voltage such that the relative variation of said amplitude is approximately half of the relative variation of said direct voltage, the internal resistance R of said amplifying element, the impedance Z of said coil transferred to said other end of said primary winding, and the internal impedance Z /n of the secondary side of said transformer transferred to the primary side, being related as follows:
  • n is the transformation ratio of said transformer, a negative feedback circuit, means coupling the input of said feedback circuit to the primary Winding of said transformer, and means coupling the output of said feedback circuit to the input circuit of said amplifying element.

Landscapes

  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Details Of Television Scanning (AREA)
US793483A 1958-02-15 1959-02-16 Circuit arrangement to produce a sawtooth current in a coil and a direct voltage Expired - Lifetime US3061757A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL224964 1958-02-15

Publications (1)

Publication Number Publication Date
US3061757A true US3061757A (en) 1962-10-30

Family

ID=19751126

Family Applications (1)

Application Number Title Priority Date Filing Date
US793483A Expired - Lifetime US3061757A (en) 1958-02-15 1959-02-16 Circuit arrangement to produce a sawtooth current in a coil and a direct voltage

Country Status (9)

Country Link
US (1) US3061757A (no)
CH (1) CH374387A (no)
DE (1) DE1083857B (no)
DK (1) DK108871C (no)
ES (1) ES247201A1 (no)
FR (1) FR1225034A (no)
GB (1) GB915554A (no)
LU (1) LU36855A1 (no)
NL (2) NL224964A (no)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3217236A (en) * 1960-06-24 1965-11-09 Philips Corp Circuit arrangement for producing a comparatively high voltage utilizing voltage dependent resistors
US3377501A (en) * 1963-08-12 1968-04-09 Philips Corp Line deflection circuit for use in television receivers with a frequency-dependent network connecting the feedback control circuit with the control electrode of the output amplifier
US3440484A (en) * 1965-05-21 1969-04-22 Gen Electric Retrace pulse shaping in a transistor vertical deflection circuit
US3450935A (en) * 1965-03-15 1969-06-17 Rca Corp Protection circuit
US3517253A (en) * 1968-05-22 1970-06-23 Rca Corp Voltage regulator

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1562292B1 (de) * 1961-07-13 1970-05-14 Philips Patentverwaltung Saegezahn-Schaltungsanordnung mit Regelung
DE1185217B (de) * 1962-03-03 1965-01-14 Fernseh Gmbh Schaltungsanordnung fuer Fernsehgeraete zur gleichzeitigen Regelung der Bildhoehe und Bildbreite

Citations (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2579627A (en) * 1950-06-22 1951-12-25 Rca Corp Deflection system
US2584213A (en) * 1950-05-01 1952-02-05 Rca Corp Amplifying system
US2697798A (en) * 1949-08-12 1954-12-21 Motorola Inc High-voltage regulation system
US2712092A (en) * 1955-06-28 schwarz
US2712616A (en) * 1953-03-02 1955-07-05 Gen Electric Cathode ray beam deflection circuits
US2729766A (en) * 1951-02-07 1956-01-03 Rca Corp Electronic oscillator circuits
US2740070A (en) * 1952-03-15 1956-03-27 Philco Corp Horizontal deflection system for television receiver
US2743382A (en) * 1954-03-26 1956-04-24 Rca Corp Deflection circuits
US2751520A (en) * 1952-03-21 1956-06-19 Rca Corp Power supply regulation
US2790108A (en) * 1953-08-24 1957-04-23 Raytheon Mfg Co High voltage control in television receivers
US2810093A (en) * 1955-03-31 1957-10-15 Rca Corp Circuitry for overcoming raster bending
US2856560A (en) * 1955-08-19 1958-10-14 Bell Telephone Labor Inc Automatic picture size control
US2872616A (en) * 1956-12-26 1959-02-03 Sylvania Electric Prod Power supply

Patent Citations (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2712092A (en) * 1955-06-28 schwarz
US2697798A (en) * 1949-08-12 1954-12-21 Motorola Inc High-voltage regulation system
US2584213A (en) * 1950-05-01 1952-02-05 Rca Corp Amplifying system
US2579627A (en) * 1950-06-22 1951-12-25 Rca Corp Deflection system
US2729766A (en) * 1951-02-07 1956-01-03 Rca Corp Electronic oscillator circuits
US2740070A (en) * 1952-03-15 1956-03-27 Philco Corp Horizontal deflection system for television receiver
US2751520A (en) * 1952-03-21 1956-06-19 Rca Corp Power supply regulation
US2712616A (en) * 1953-03-02 1955-07-05 Gen Electric Cathode ray beam deflection circuits
US2790108A (en) * 1953-08-24 1957-04-23 Raytheon Mfg Co High voltage control in television receivers
US2743382A (en) * 1954-03-26 1956-04-24 Rca Corp Deflection circuits
US2810093A (en) * 1955-03-31 1957-10-15 Rca Corp Circuitry for overcoming raster bending
US2856560A (en) * 1955-08-19 1958-10-14 Bell Telephone Labor Inc Automatic picture size control
US2872616A (en) * 1956-12-26 1959-02-03 Sylvania Electric Prod Power supply

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3217236A (en) * 1960-06-24 1965-11-09 Philips Corp Circuit arrangement for producing a comparatively high voltage utilizing voltage dependent resistors
US3377501A (en) * 1963-08-12 1968-04-09 Philips Corp Line deflection circuit for use in television receivers with a frequency-dependent network connecting the feedback control circuit with the control electrode of the output amplifier
US3450935A (en) * 1965-03-15 1969-06-17 Rca Corp Protection circuit
US3440484A (en) * 1965-05-21 1969-04-22 Gen Electric Retrace pulse shaping in a transistor vertical deflection circuit
US3517253A (en) * 1968-05-22 1970-06-23 Rca Corp Voltage regulator

Also Published As

Publication number Publication date
NL224964A (no)
NL113455C (no)
CH374387A (de) 1964-01-15
DK108871C (da) 1968-02-19
ES247201A1 (es) 1959-06-01
FR1225034A (fr) 1960-06-28
LU36855A1 (no)
GB915554A (en) 1963-01-16
DE1083857B (de) 1960-06-23

Similar Documents

Publication Publication Date Title
US3742242A (en) High and low voltage regulating circuit
US2697798A (en) High-voltage regulation system
US2579627A (en) Deflection system
US3049640A (en) Self regulating deflection circuits
US3061757A (en) Circuit arrangement to produce a sawtooth current in a coil and a direct voltage
US3706023A (en) High voltage regulation circuit for television receiver
US3868538A (en) Ferro-resonant high voltage system
US2458532A (en) Cathode-ray tube circuit
US2712092A (en) schwarz
US2577112A (en) High-voltage power supply regulation
US2944186A (en) Circuit arrangement for producing a sawtooth current in a coil
US3077550A (en) High voltage power supply regulation
US2621305A (en) Cathode-ray tube power supply
US2628326A (en) Television apparatus
US3375436A (en) Regulated high voltage d.c. power supply
US2485652A (en) Regulated radio frequency power supply
US3051888A (en) Circuit arrangement for stabilizing the amplitude of a high direct voltage
US2598134A (en) Power conservation system
US3798497A (en) Solid-state television receiver with magnetically regulated power supply
US2651739A (en) Brightness control circuit for television receivers
US3621123A (en) High-voltage regulation circuit for a color television receiver
US2555832A (en) Cathode ray deflection system
US3113237A (en) Adjustable voltage supply
US2843796A (en) Power supply regulation
US3202865A (en) Regulated high voltage supplies for color television tube